Doubling time and annual doubling rate of human prostatic cancer

The doubling time (DT) of human prostatic cancer is calculated for the first time; its various parameters and the relative importance of each are reviewed. A crude volume-doubling time (DTcv), a theoretical doubling of the number of cells (DTt), and an annual doubling rate (ADR), are defined and calculated for each of 12 patients who had undergone needling of the prostate for diagnostic purposes and in whom tumor cells were implanted in the track of the biopsy needle and had grown into a subcutaneous perineal nodule. The harmonic average DTcv was six days and DTt eight days, and the average ADR was 45 doublings per year. From the study of the calculated DTs and ADRs, it became obvious that the 12 patients fell into three distinct groups: Group I = slow tumor growth rate, an average ADR of 9 doublings per year, and a harmonic average DTt of forty days; Group II = medium tumor growth rate, an average ADR of 35 doublings/year, and a harmonic average DTt of ten days; and Group III = rapid tumor growth rate, an average ADR of 100 doublings/year, and a harmonic average DTt of four days.